I read the same thing. I tested for it by extracting the bullet from the case, emptied the powder, and discharged the primer. Then took a torch to the empty case. No lacquer ran off. So i figured it was “urban legend”
I was wrong about one thing. The ratio was 1 brass to 9 steel.
http://www.freerepublic.com/focus/f-chat/2888468/posts